Updated Genetics Testing

Thought I’d pass along some things I learned about genetics this week and give an update on my “mutation of unknown significance” (doesn’t that sound fancy?). This is a long post so if you only care about the main point, I will first provide an “executive summary”, or “back-of-the-book” summary, if you will. 😉 The main point is that I found out this week that my mutation of unknown significance, which they found in my genetic testing back in 2009, has come back conclusively to not be a concern (or not to have a link with breast cancer – good news). The second point is that they have some new advancements in genetic testing that they wanted me to get tested for, which I did this morning and should get the results back in 2-6 weeks. Ok, that was the “executive summary”. Now for my usually long-winded post in case you want more details or care to learn something further…… 🙂

Before I go into details of this week, let me recap/clarify a few points. First, each person’s body has approximately 25,000 genes. Each gene has a different and very specific function. There are many genes that are considered cancer suppressant genes. In a normal person, these genes help regulate cell division/growth and prevent cancer (abnormal / out-of-control cell growth). If any of the cancer suppressant genes are mutated (which can happen hereditarily at birth or sometime after from environmental causes), they can cause an increased risk of cancer because they don’t perform their purpose of properly regulating cell growth.

The genes most closely related to breast cancer are BRCA1 and BRCA2. People often get confused about this and ask “do you have the BRCA gene?” Really though, everyone has these genes (even men) – what they really should ask is “do you have a BRCA mutation” because the “mutations” are what cause the concern. Another common misconception is that breast cancer is usually hereditary. People are often surprised to hear when someone gets breast cancer when it doesn’t run in their family. But in fact, only 10% of breast cancers are actually hereditary. The remaining 90% of cases are due to age (risk increases from age 40-50 and beyond), environment, unknown reasons, etc. Another startling statistic, particularly for me, is that less than 1.5% of breast cancers occur in people under the age of 30. Aren’t I special. 🙂

Ok, so back in 2009 when I was first diagnosed with breast cancer, I underwent the standard genetic testing (looking for mutations in the BRCA1 and BRCA2 genes). They found a mutation in one of the genes (can’t remember which one) but it was one of “unknown significance”. They said I was 1 of only 4 people in the history of the genetic testing that had this same mutation. Basically, there are dozens (or hundreds?) of possible mutations in these genes. Many have a “known” link with breast cancer. Many are known not to have a link. Then there are those they don’t know much about. Of course mine was one of those. Basically, if you have a BRCA1 or BRCA2 “mutation” with a “known” link with breast cancer, they automatically recommend a double mastectomy and hysterectomy because there is an 80-90% chance that the breast cancer would come back and also a high risk of ovarian cancer on top of all that. Since my mutation was of “unknown significance”, they said it was up to me whether I wanted to opt for more aggressive surgery, or not. After chemo and my updated MRI results, I opted not to have the more aggressive surgery. The genetics lab said they would keep my information on file and would call when they had more information about whether further testing would prove a link, one way or the other.

Well, that call came very unexpectedly, and out-of-the-blue, on Monday. I got back to my desk from a meeting and heard the voicemail. I freaked and immediately went to the phone room to return the call. Thankfully, they said the mutation I have has been shown NOT to have a link with breast cancer – GREAT NEWS. They went on to say though that there have been some advancements in the BRCA testing and other genetics testing that they thought I should come in for given my diagnosis at such a young age (30). I had that appt today. Here’s what I learned from that appt:

Ok, so think of a gene like a sentence. A “mutation” would be like a misspelled word, or one letter that is missing or different than it should be. That’s what they tested me for back in 2009. They now have new advancements, where they also look for sequence re-arranging. So, if you think of a sentence again, it would be like re-arranging words or moving a word (or group of letters) to somewhere in the sentence where the sentence would no longer make sense. They said the BRCA testing I had done back in 2009 would have detected 90-95% of any mutation concerns. The genetics counselor I met with today said she thinks the chances are 1-2% that this new updated test (which they have been doing since early 2011) will reveal anything newly concerning for me.

Another gene they are now testing for (which they weren’t in 2009, at least not routinely) is called P53, which I’ve never heard of until now. This is another cancer suppressant gene, but it affects many different types of cancer, not just breast cancer. Everyone has this gene too. Its purpose is to suppress the abnormal growth of cells (cancer) in soft tissue. People with a mutated P53, which is caused at birth mostly, but could also be affected by environmental causes over one’s lifetime (such as UV exposure, alcohol use, etc.), have a higher chance of developing cancers at a young age, which they consider to be 30 and younger. The P53 mutation is associated with breast cancer, sarcomas, leukemia, thyroid, colon, and many others. They said the chance of me having a P53 mutation (given my age at diagnosis, which is why they’re testing me for it) is 7%. If it comes back that I have a P53 mutation, they would recommend the same thing as they would for BRCA mutations, but there would also be increased chances of those other cancers, where screening is less common so it would just involve keeping a close eye.

They said there are several other genes that they have new technology for, and genetic biologists are on the horizon of knowing how to interpret those results. She said I should call back in a year (and annually thereafter) to see where they are with the latest advancements. I’m still somewhat convinced all the fertility stuff caused my cancer, but she doesn’t seem to think so. Dr. Limentani also doesn’t think so – he just said he thought it made the cancer come on more aggressively/earlier but that I would have gotten it eventually. Who knows.

So anyway, the statistics are in my favor (1-2% and 7% aren’t bad), but I opted to move forward with the updated testing just for peace of mind. They drew blood today and have sent it off to Myriad and Baylor (genetics research/testing labs). I should get the BRCA results back in 2 weeks and the P53 back in 4-6 weeks. Hopefully you are still awake and I didn’t completely waste your time with that snooze-fest. That is all, good day sir. 😉


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